Motion-picture machine.



C. F. JENKINS.

MOTION PICTURE MACHINE. APPLICATION FILED MAR. 20. I913.

Patented May 8, 1917.

CHARLES FRANCIS JENKINS, OF WASHINGTON, DISTRICT OF COLUMBIA.

MOTION-PICTURE MACHINE.

- Specification of Letters Patent. 1

Patented May 8, 191 '7.

Application filed March 20, 1913. seriaiNo. 755,752.

To all whom'it may concern:

Be it known that 1, CHARLES FRANCIS JENKINS, a citizen of the UnitedStates, residing at Washington, in the District of Columbia, haveinvented certain new and useful Improvements in Motion-Picture Machines,ofwhich the following is a specification, reference being had therein tothe accompanying drawing. i

Municipal regulations in perhaps most places now require motion pictureprojecting apparatus to be operated in the interior of a fireproofchamber or cabinet because experience has shown it practicallyimpossible to use ordinary apparatus without great danger of ignition,and because the burning of a large film roll produces intense heat,while it is impossible to extinguish the until the entire film roll isconsumed. These facts havetprevented and still prevent the free use of"simple projecting apparatus in homes, schools, churches, and the like.

The object of this invention is to lessen. the dangers indicated, andparticularly to make ignition of the film far less probable, since bythis step coupled with others, not here set forth, I have producedsimple projecting apparatus which will not ignite the film even thoughthe film feed cease for any interval while the light remains directlyupon the film.

In the accompanying drawings,

Figure 1 is a plan view of my apparatus.

Fig. 2 is a side view of a shutter of standard construction.

In these figures, A. represents a casing containing a small light B anda condensing lens C, D a frame plate provided with the The usual shutterof this class is so cut away as to allow only about forty per cent. ofthe light falling upon it to pass to the film and thence to the screen.Since the film and screen are without light about sixty per cent. of thetime, a powerful light is required, and as heat increases withthe lightand the shutter is usually interposed in the path of the beam passingfrom the film to the screen, this powerful light and the strongheat raysfall continuously upon the film,w1th the result that stopping of thefilm, even for a very short interval, causes it to be ignited,especially since the apertured plate and the film' guide at the aperturegradually accumulate heat and necessarily reach a somewhat hightemperature. I avoid much of'the difliculty by placing the shutterbetween the light source and the in the path of the light at a certainpoint,

usual aperture across which the film is passed step by step, E a prismdeflecting the light coming through the aperture through a projectinglens F to any screen or the like (not shown) and away from the filmrolls. G represents a shutter interposed between the source of light andthe apertured plate and film exposed at the aperture and rotated at theproper speed by any suitable means.

film and at some distance from the latter. By this means alone aboutsixty per cent. of the heat is intercepted and never reaches the film,and at the same time the parts about the film are prevented frombecoming hot. The-thin portion of the shutter receiving all thisintercepted'heat is well adapted to radiate it since it rotates in freeair.

What I claim is:

1. The combination with a source of light" and means for properlypresenting. the film of a moving apertured shutter located in freecooling air and in the path of the light from its source to said point.

2. The combination with a light, a condensing lens, and a plate havingan exposure aperture, of a rotary shutter interposed between said lensand exposure aperture and forming the sole means of interrupting a.light beam passing from said lens to said aperture, said plate andshutter being located in free cooling air.

In testimony whereof I affix my signature in presence of two witnesses.

CHARLES FRANCIS JENKINS.

Witnesses:

J. R. WHITE, JAMEs L. CRAWFORD.

